Fig. 1: The chromophores and wavelength sensitivity of the new multi-centre photocobilin photoreceptors.
From: Photocobilins integrate B12 and bilin photochemistry for enzyme control
Schematic showing the structures of the adenosylcobalamin (AdoCbl or coenzyme B12) and biliverdin (BV) chromophores in photocobilin, together with the wavelength range over which they absorb. The photocobilins are found as both standalone proteins or fused to other domains (a diguanylate cyclase or DGC domain is shown). The nature of the upper R ligand in B12 is responsible for the different B12 analogues (R=adenosyl, AdoCbl; = CH3, methylcobalamin; = OH, hydroxcobalamin; =CN, cyanocobalamin). The protein (surface is coloured blue and orange by chains) and absorbance spectrum shown in the figure is from the SasPcob protein with bound AdoCbl and BV under dark conditions.
